• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1512-1515
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• 2004

In this study, we investigated in vitro nitric oxide (NO) scavenging effect on nine herbal extracts using an NO donor S-nitroso-N-acetylpenicillamine (SNAP) compared with vitamin C. All herbal extracts effectively reduced the generation of NO radicals in a dose-dependant manner and over 65% in 10h. Especially, Ephedrae herba, Carthami flos and Lonicerae flos declined over 75% of NO scavenging effect, suggested that the herbal extracts are the powerful free radical scavengers and may be effective in clinical applications.

• Natural Product Sciences
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• v.14 no.3
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• pp.202-205
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• 2008

The antioxidant activity of Paeonia suffruticosa (Paeoniaceae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of P. suffruticosa showed the strong antioxidant activity. The antioxidant activity of ethyl acetate soluble fraction was stronger than that of the others ($IC_{50}$, $1.2\;{\mu}g/mL$), and the fraction was subjected to purification by repeated silica gel and Sephadex LH-20 column chromatography. Suffruticosol A, suffruticosol B, methyl gallate, and gallic acid, were isolated from the ethyl acetate soluble fraction. Their structures were elucidated by physico-chemical and spectroscopic studies.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.332-333
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• 2008

• BMB Reports
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• v.39 no.3
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• pp.335-338
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• 2006

Methylglyoxal (MG) is an endogenous physiological metabolite which is present in increased concentrations in diabetics. MG reacts with the amino acids of proteins to form advanced glycation end products. In this in vitro study, we investigated the effect of MG on the structure and function of ceruloplasmin (CP) a serum oxidase carrier of copper ions in the human. When CP was incubated with MG, the protein showed increased electrophoretic mobility which represented the aggregates at a high concentration of MG (100 mM). MG-mediated CP aggregation led to the loss of enzymatic activity and the release of copper ions from the protein. Radical scavengers and copper ion chelators significantly prevented CP aggregation. CP is an important protein that circulates in plasma as a major copper transport protein. It is suggested that oxidative damage of CP by MG may induce perturbations of the copper transport system and subsequently lead to harmful intracellular condition. The proposed mechanism, in part, may provide an explanation for the deterioration of organs in the diabetic patient.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.328-335
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• 1996

Effects of hydrogen peroxide$(H_2O_2)$ on polyphenol oxidase (PPO) in Perillae Folium were investigated. The inactivation of this enzyme was dependent on $H_2O_2$ concentration. and the initial lag period was not shown. Preincubation of Perillae Folium PPO with $H_2O_2$ in the absence of a substrate resulted in rapid loss of enzymatic activity. The inactivation of PPO by $H_2O_2$ dependents temperature and pH. OH radical scavengers such as mannitol and sodium formate did not protect the enzyme against inactivation by $H_2O_2$. Substrate analogue such as phenylalanine protected the enzyme against inactivation by $H_2O_2$. and copper chelator such as sodium azide also protected the enzyme.

• Journal of the Korean Magnetic Resonance Society
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• v.11 no.1
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• pp.56-63
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• 2007

A series of bromophenols and corresponding debrominated phenolic compounds was prepared by isolation from red alga Tichocarpus crinitus and by structural modification of natural bromophenols. Their structures were determined by extensive NMR analysis and the antioxidant activities were established through the determination of their abilities to inhibit free radicals using DPPH as the stable radical. The most active free radical scavengers were the debrominated phenolic derivatives 3,4-dihydroxybenzyl alcohol and 3,3',4,4'-tetrahydroxydiphenylmethane.

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.137-139
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• 2013

Free radical scavengers in the bisdemethoxycurcumin (BDMC), demethoxycurcumin (DMC) and curcumin of turmeric (Curcuma longa) were screened, identified, quantified and isolation using coupled off-line-2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and on-line screening high-performance liquid chromatography (HPLC)-ABTS assay. There was a very small margin of error between the off-line-ABTS method and the on-line screening HPLC-ABTS method.

• Environmental Engineering Research
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• v.19 no.1
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• pp.41-45
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• 2014

The peels of Carya cathayensis Sarg. (PCCS) were treated under subcritical water conditions ($130^{\circ}C$ to $280^{\circ}C$ for 0 to 120 min). The extract from PCCS included reducing sugar, proteins, and compounds with radical scavenging activity. Addressing the reducing sugar that is a resource of bioethanol, we could maximize the reducing sugar under the subcritical water ($190^{\circ}C$ for 60 min) and obtain 0.24 g/g-sample together with 9.7 units/mg-sample of radical scavenging activity. The obtained extract was estimated to correspond to 1 L of bioethanol/100 g-sample. It was therefore considered that the treatment by subcritical water could yield reducing sugar and natural compounds with radical scavenging activity.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.233-237
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• 2000

As part of a continuing investigation to identify free radical scavengers from the fruit bodies of basidiomycetes, we isolated two p-terphenyl compounds, designated as PAl and PA2l, from cethanolic extract of the fruit body of Pasillus panuoides. The methanolic extract was processed by ethyl acetate extraction and silica gel column chromatography to yield two active fraction. PAl was obtained from one of the fractions through Sephadex LH-20 and silica gel column chromatographies and reverse-phase HPLC. The other fraction was purified by Sephadex LH-20 and reverse-phase column chromatographies to produce PA2. The compounds PA1 and PA2 were identified as leucomentin-4 and leucomentin-2, respectively, on the basis of various spectroscopic analyses. These compounds exhibited strong inhibitory activities against lipid peroxidation in rat liver microsomes with IC_{50}$ values of 0.10 and $0.06{\;}\mu\textrm{g}ml$, respectively.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.